What is the Peripeteia and Catharsis in the play Macbeth and how is it demonstrated?

"Perepetia" is when a Greek hero realizes everything he believed in is wrong. "Catharsis" is  defined as

1. A purifying or figurative cleansing of the emotions, especially pity and fear, described by Aristotle as an effect of tragic drama on its audience.


2. A release of emotional tension, as after an overwhelming experience, that restores or refreshes the spirit.

In Macbeth there are two key points where he experiences Perepetia. The first occurs just after the killing of Duncan and before Macbeth arranges the murderers to kill Fleance and Banquo. Macbeth says he is "I am in blood / Stepp'd in so far, that, should I wade no more, / Returning were as tedious as go o'er" (3.4). Macbeth was undecided about killing Duncan at first, remember, and it was his wife who pressured him into doing the deed.

The second instance of perepetia is MacBeth`s infamous

To-morrow, and to-morrow, and to-morrow,
Creeps in this petty pace from day to day,
To the last syllable of recorded time;
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more. It is a tale
Told by an idiot, full of sound and fury
Signifying nothing." (5.5.17-28)

Here Macbeth is at his absolute lowest, realizing that his play is over and his actions have amounted to little more than the rantings and strutting of himself, the poor player.

Catharsis is experienced at the end of the play when the audience sees justice done and balance restored when Macduff beheads the traitorous King and mounts his head upon a pike for all to see.